import java.util.Scanner;
import java.math.*;
public class 关于圆的计算 {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        System.out.println("输入圆的半径(cm)");
        double r = in.nextDouble();
        jisuan zong = new jisuan();
        zong.C(r);
        zong.S(r);
    }
}
class jisuan{
     public  void C(double r){
         double C;
         C = 2*Math.pow(r,2)*Math.PI;
         System.out.println("圆的周长是"+String.format("%.2f",C)+"cm");
     }
    public  void S(double r){
        double S;
        S = Math.PI*Math.pow(r,2);
        System.out.println("圆的面积是"+String.format("%.2f",S)+"cm");
    }

}